The present invention is related to bearing assemblies of a wheel end for a motor vehicle.
Wheel ends and bearing assemblies for motor vehicles are known and have been widely used in the automotive industry for many years. A typical wheel end of a vehicle includes a bearing assembly which is mounted to a steering knuckle by means of fasteners or interference fittings. For example, a bearing assembly may include an inner race having raceways formed thereon and an outer race having raceways formed thereon wherein the inner and outer races cooperate with each other to house ball bearings within the raceways.
Although current bearing assembly designs are adequate, bearing assembly and wheel end manufacturers have been challenged in with weight, mass, deflection, corrosion, and packaging issues. For example, many of the current designs of bearing assemblies include a relatively high weight and mass requirement. Many bearing assemblies include a mounting flange and relevant fasteners associated therewith to mount the bearing assembly to the steering knuckle. Such components add to the weight, mass, and packaging complexity of the bearing assembly. Moreover, a typical outer race and steering knuckle interface creates a deflection. Such deflection may cause brake roughness and vehicle cornering issues during normal operation of the vehicle. Moreover, for strength and stiffness, the bearings or outer races of the bearings typically are made of adequate material such as steel.
Thus, it is one aspect of the present invention to provide a bearing assembly of a wheel end for a motor vehicle wherein the bearing assembly reduces the typical weight of the wheel end, lessens the packaging complexity, and lessens the deflection at a bearing-to-knuckle mounting interface.
It is another aspect of the present invention to provide a bearing assembly of a wheel end for a motor vehicle. The bearing assembly includes a steering knuckle having an inner wall formed through its body to define a center bore. The inner wall includes inboard and outboard outer raceways integrally formed thereon. The inboard and outboard outer raceways formed on the inner wall essentially eliminates a need for an outer race which would otherwise engage with the knuckle creating an additional interface for increased deflection, weight, and package size. Thus, the steering knuckle includes an integrated outer race having inboard and outboard outer raceways formed thereon.
In one embodiment, the bearing assembly includes a hub including a flange and a hub shaft. The flange extends from the hub shaft at the outboard end and the hub shaft is disposed in the center bore of the knuckle at the inboard end. The hub shaft has a first raceway formed thereon adjacent the outboard end of the hub shaft. The first raceway is configured to cooperate with the outboard outer raceway of the steering knuckle to house rolling elements to constitute a first bearing. The shaft of the hub further includes a stepped boss formed thereon adjacent the inboard end of the hub shaft. The bearing assembly further comprises an inner race disposed in the stepped boss wherein the inner race has a second raceway formed thereon adjacent the inboard end of the hub shaft. The second raceway is configured to cooperate with the inboard outer raceway of the steering knuckle to house rolling elements to constitute a second bearing.
In another embodiment, first and second inner races are disposed on an outer surface of the hub shaft. The first inner race has a first raceway formed thereon adjacent the outboard end of the hub shaft and configured to cooperate with the outboard outer raceway of the steering knuckle to house rolling elements to constitute a first bearing. The second inner race has a second raceway formed thereon adjacent the inboard end of the hub shaft and configured to cooperate with the inboard outer raceway of the steering knuckle to house rolling elements to constitute a second bearing.
In yet another embodiment of the present invention, the bearing assembly houses tapered rollers. In this embodiment, the inner wall of the steering knuckle includes inboard and outboard raceways configured to receive tapered bearing rollers. The hub shaft has a first raceway formed thereon adjacent the outboard end of the hub shaft. The first raceway is configured to cooperate with the outboard outer raceway of the steering knuckle to receive tapered rollers to constitute a first bearing. The hub shaft includes a stepped boss formed thereon adjacent the inboard end. The inner race is disposed in the stepped boss and has a second raceway formed thereon to receive tapered rollers to constitute a second bearing, cooperates with the inboard outer raceway of the inner wall of the steering knuckle.